According to one aspect, the present invention relates to a method of adjusting the horizontal distance or span between the legs of a U-shaped boat transporter, hereinafter referred to generally as boat wagon, that includes two legs and a part which interconnects the front parts of said legs.
According to a second aspect, the present invention relates to a boat wagon with which the horizontal distance between the legs, or the leg span, can be adjusted and fixed to a wagon width suited for road transport and to a wagon width suited for boat transport.
More specifically, the invention relates to a wagon which can be pushed along an underlying supporting surface by a vehicle or moved along said surface by machinery installed to this end, and even more particularly to a boat wagon intended especially for transporting boats over short distances, such as from a position in which the boat floats in water to a trestle structure on land, or vice versa. The boat wagon is also sometimes referred to as a trailer.
The invention particularly relates to a two-axle or multi-axle wagon which includes a frame structure, a number of wheels co-acting with said frame structure, at least one support means for supporting the forward part of the boat, and one support means for supporting the rear part of the boat.
It will be noted that by the term xe2x80x9caxlexe2x80x9d as used here and in the following description includes both a single axle and a bogie.
The present invention can be seen as a further development of the boat wagon illustrated and described in Swedish Patent Application 97 01221-5.
Various types of wagons or trailers that are adapted to transport boats over short distances and which can be pushed or moved along an underlying support surface are known to the art.
One such wagon or trailer is illustrated and described in Swedish Patent Publication SE-C1-501 759, which clearly defines the earlier standpoint of techniques in the present regard.
With respect to features associated with the present invention, it should be mentioned that boat wagons that include a U-shaped frame structure with which the horizontal distance between the legs can be adjusted to correspond to the width of a boat are known to the art.
In this regard, it is known to include at the front part of respective legs a glide sleeve which is heavily dimensioned to accommodate torsional stresses and slideable along a cross beam which functions to interconnect said legs.
The length of the cross-beam is adapted to the greatest width or span between the legs.
Also known to the art are boat transport wagons that are equipped with a number of lashings for securing the hull of a boat to the wagon. Boat transport wagons that have fixed support points for holding the hull of a boat to the wagon.
When taking into consideration the technical deliberations that a person skilled in this particular art must make in order to provide a solution to one or more technical problems that he/she might encounter, it will be seen that on the one hand it is necessary initially to realise the measures and/or the sequence of measures that must be undertaken to this end, and on the other hand to realise which means is/are required in solving one or more of said problems. On this basis it will be evident that the technical problems listed below are highly relevant to the development of the present invention.
When considering the present state of the art, as described above, it will be evident that a technical problem resides in providing structural details with the aid of simple means that will enable the legs of the U-shaped frame structure of a trailer or boat wagon, by all means of the kind defined in the introduction, to be adjusted to different spans, for instance to a narrow span at which the wagon can be moved conveniently along a road, such as along narrow road sections, and a broader span at which the wagon can stably transport broad boats.
Another technical problem is one of realising the benefits that are obtained when the leg-interconnecting member comprises several sub-parts or is telescopic so as to enable one and the same boat wagon to be adapted to a smallest width suitable for road transport to a width and configuration suitable for transportation of a given boat construction.
In addition, a technical problem resides in creating to this end conditions which will enable the leg-interconnecting member of the frame construction to be comprised of several sub-parts without deleteriously affecting the requisite mechanical strength and torsional rigidity of the leg-interconnecting member and without needing to provide glide sleeves for said legs.
With regard to the aspect of flexural rigidity, a further technical problem is one of allowing the leg-interconnecting member to consist of at least a number of readily removable sub-parts, so as to enable said leg-interconnecting member to be adjusted to a length that corresponds to the chosen distance between said legs.
Another technical problem is one of dimensioning said leg-interconnecting member and its sub-parts with requisite coupling means such that said sub-parts will exhibit a torsional rigidity and mechanical strength adapted to the construction of the boat wagon and dimensioned for a chosen maximum displacement or boat weight and/or weight distribution.
Yet another technical problem is one of realising the significance of providing mutually opposite end sections of a removable sub-part with first coupling means adapted for co-action with corresponding second coupling means belonging to adjacent leg-related sub-parts of said leg-interconnecting part, and to mutually adapt said second corresponding coupling means to form corresponded coupling means therebetween.
Another technical problem in respect of boat wagons of the kind in question resides in providing conditions with the aid of simple means such that each leg and associated wheels will be balanced as a unit and therewith be able to rest on an underlying surface without tipping.
Another technical problem with a boat wagon of the kind in question is one of providing conditions with the aid of simple means such that telescopically-related rods can extend parallel with said leg-interconnecting member or such that the interconnecting member can be formed telescopically.
Another technical problem with boat wagons of the kind concerned resides in the provision of conditions with the aid of simple means such that released or non-secured legs can be moved closer together or further apart with the aid of said steerable wheels and drive means constructed to this end.
Still another technical problem with boat wagons of the kind concerned resides in the provision of conditions with the aid of simple means that allow the leg-interconnecting member to be comprised of at least two parallel beam-sections of which each is provided with one or more readily removed sub-parts or, alternatively, are telescopically related.
When considering the prior state of the art as described above, it will be seen that a technical problem also resides in providing a simple construction for a two-axle wagon or trailer of the aforedescribed kind that cannot only be used to transport boats reliably with the aid of support straps or the like in a simple fashion, essentially regardless of the shape of the hull of the boat, but which will also enable the boat""s attitude in relation to its horizontal plane to be readily adjusted, generally independently of the position or the status of the wagon at that moment in time, therewith enabling the position of the boat relative to the horizontal plane to be kept more or less constant despite pronounced changes in the attitude of the wagon as a result of moving up and down in the water or moving along a sloping or irregular surface and also of providing conditions in which each of two support means is able to utilize a respective rotatable or pivotal arm to move a support strap or belt up and down in a plane, or adjacent to a plane, which extends perpendicularly to the frame structure, whilst the keel of the hull is able to rest on a support plate.
It will also be seen that a technical problem resides in realising the advantages that are afforded when the support plate is mounted on a part of a leg-interconnecting member and is arranged for movement solely horizontally in the longitudinal extension of said interconnecting member, so as to enable the most forward part of the hull of said boat to be moved sideways when adjusting the position of the hull with one or both of said support straps.
Another technical problem is one of realising the significance of and the advantages afforded by allowing the forward part of the boat wagon to be raised and lowered through the medium of piston-cylinder devices active between the forward steerable wheels and the wagon frame-structure.
In the case of this latter application, another technical problem is one of realising the benefits that are afforded when the side-mounted piston-cylinder devices are connected in parallel so that the two such devices will generate mutually identical pressure forces on the one hand and provide a pendulating function on the other hand, so as to compensate for irregularities and unevenness in the surface on which the wagon is supported.
With the intention of solving one or more of the aforesaid technical problems, the present invention takes as its starting point a wagon or trailer of the aforesaid construction that can be pushed or moved along an underlying surface supporting said wagon.
The invention relates to a method of adjusting the distance between the legs of a U-shaped boat wagon to a span suitable for road transport and to a span suitable for boat transport.
The invention also relates to a boat transport wagon where the leg-interconnecting member is a multi-part structure in which the parts removably co-act with each other and/or co-act telescopically with each other, where one or more removed parts and/or telescopically compressed parts result in a span between the legs and therewith a wagon width that is suitable for road transport, and where one or more additional parts fitted to said member and/or a part or parts telescopically extended from a telescopic member will result in a leg span suitable for boat transport.
According to proposed embodiments of the invention, the boat transport wagon comprises a frame structure, a plurality of wheels which co-act with the frame structure and which are allocated one front steerable and load-bearing axle and at least one rear load-bearing axle, at least one support means for supporting the forward part of the boat, and a support means for supporting the stern-part of the boat, wherein the frame structure has a U-shape in the horizontal plane, wherein the outer parts of respective legs co-act with wheels mounted on the rear load-bearing axles whereas a member that interconnects the inner parts of the legs co-acts with wheels mounted on the front, steerable axles, wherein the support means for supporting the forward or midship region of the boat can be raised and lowered by means of two parallel, hydraulically activatable, side-mounted piston-cylinder devices, and the support means for supporting the stern region of the boat can also be raised and lowered by means of two parallel, hydraulically activatable and side-mounted piston-cylinder devices.
The present invention also utilises the earlier known feature of including in the support means for supporting the forward region and/or midship region of the boat and the support means intended for supporting the stern region of the boat a respective belt, prop, support strap or like device.
In the case of a wagon of this nature, it is also proposed that the leg-interconnecting member is comprised of a number of sub-parts of which at least one can be readily removed, that mutually opposing end regions of said removable sub-parts are provided with first coupling means for co-action with corresponding second coupling means on adjacent leg-related sub-parts of said leg-interconnecting member, and that said second corresponding coupling means are also adapted to form corresponding coupling means between themselves.
According to one embodiment, the interconnecting member has the form of a beam structure.
The first and the second coupling means will conveniently comprise flanges and screw joints.
It is also proposed that each leg and its associated wheels shall be balanced and capable of supporting against an underlying surface in an upright position.
According to another embodiment, telescopically related rods extend parallel with said interconnecting member.
In the case of a divided interconnecting member, the legs can be moved apart or closer together by means of said steerable wheels and with the aid of drive machinery.
It is also proposed that said interconnecting member comprises at least two parallel beam sections that each have a readily removed centre sub-section.
It is specifically proposed by the present invention that a support plate mounted on a boat wagon adapted for the forward region of the hull of the boat shall be mounted on a central or midway sub-part of an interconnecting member and be movable horizontally in the longitudinal extension of said member, so as to be able to move the most forward part of the hull sideways when adjusting the position of the hull with the aid of one or both of said support straps.
It is also proposed to enable the forward part of the boat wagon to be raised and lowered with the aid of side-mounted piston-cylinder devices that act between the front steerable wheels and the wagon frame-structure.
In this latter application, it is proposed that the side-mounted piston-cylinder devices are connected in parallel so that both devices will generate the same pressure forces on the one hand, and so as to provide a pendulating function on the other hand, therewith enabling irregularities in the underlying wagon supporting surface to be compensated for or taken-up without appreciably changing the position of the wagon.
Those advantages that are primarily characteristic of an inventive boat wagon reside in the provision of conditions which enable the total width of the wagon and the span between the legs of the U-shaped frame structure to be readily adjusted to a width or span suitable for road transport or to a width or span suitable for boat transport, with the aid of a multi-part leg-connecting member.
Another advantage is that the position of the hull of a boat supported by the wagon can be easily adjusted by resting the forward region of the hull on a horizontal support plate which can move along the interconnecting member.